The Shellback covers the back with a single piece of imitation tape. Its 6-mm width is suitable for gammarids, Czech nymphs, and mayfly nymphs, for which the top of the body is a highly visible feature.
The iridescent effect can also cover a larger portion of the fly: Hends cites streamer bodies and large flies among its uses. When tying, the tape is placed over the area to be covered and then secured using the fasteners specified in the pattern. The range of shades allows you to combine a base color with iridescent highlights.